Rod 1 slides in fixed guides p-p and is connected by turning pair A to pawl 4. Ratchet wheel 2 rotates about fixed axis B. When rod 1 moves to the left, pawl 4 turns ratchet wheel 2 together with the platen (roller), attached to the wheel, and the paper (not shown). The spacing between the typewritten lines is adjusted by turning lever 3 along whose lug b projection c of pawl 4 slides before the pawl engages and turns ratchet wheel 2.
$1851$LR,FD$